diff --git a/LuaEngine.cpp b/LuaEngine.cpp
index d55edbf..2efcee2 100644
--- a/LuaEngine.cpp
+++ b/LuaEngine.cpp
@@ -15,9 +15,7 @@ void check(lua_State* L, const vector<int>& typearr)
 	{
 		if (lua_type(L, i + 1) != typearr[i])
 		{
-			char tmp[128] = { 0 };
-			sprintf(tmp, "Bad argument #%d. %s expected, got %s", i + 1, lua_typename(L, typearr[i]), lua_typename(L, lua_type(L, i + 1)));
-			luaL_error(L, tmp);
+			luaL_error(L, "Bad argument #%d. %s expected, got %s", i + 1, lua_typename(L, typearr[i]), lua_typename(L, lua_type(L, i + 1)));
 		}
 	}
 }
@@ -48,6 +46,7 @@ struct Window
 	static int close(lua_State* L)
 	{
 		check(L, { LUA_TUSERDATA });
+		cout << "In Window::close" << endl;
 		Window* p = (Window*)lua_touserdata(L, 1);
 		if (p->wnd)
 		{
@@ -165,7 +164,7 @@ struct Window
 	static int create(lua_State* L)
 	{
 		check(L, { LUA_TSTRING, LUA_TNUMBER, LUA_TNUMBER });
-		cout << "In SDLWindow::Create" << endl;
+		cout << "In Window::create" << endl;
 		Window* p = (Window*) lua_newuserdata(L, sizeof(Window));
 		// Data table (for storing lua values)
 		lua_pushlightuserdata(L, p);
@@ -203,6 +202,161 @@ struct Window
 	}
 };
 
+
+struct Texture
+{
+	SDL_Texture* text;
+	int w;
+	int h;
+
+	static int close(lua_State* L)
+	{
+		check(L, { LUA_TUSERDATA });
+		cout << "In Texture::close" << endl;
+		Texture* t = (Texture*)lua_touserdata(L, 1);
+		if (t->text)
+		{
+			SDL_DestroyTexture(t->text);
+			t->text = nullptr;
+		}
+		return 0;
+	}
+
+	static void create(lua_State* L) // -2, +1
+	{
+		// 此函数由Renderer在C层直接调用. 调用前需要先放一个renderer userdata和lightuserdata在栈上, 值就是当前的SDL_Texture.
+		// 调用后栈上会留下Texture的userdata.
+		// 因此在Lua层没有直接创建Texture的方法.
+		cout << "In Texture::create" << endl;
+		Texture* p = (Texture*)lua_newuserdata(L, sizeof(Texture));
+		// Metatable
+		lua_getfield(L, LUA_REGISTRYINDEX, "__texture_mt");
+		if (lua_type(L, -1) == LUA_TNIL)
+		{
+			lua_pop(L, 1);
+			lua_newtable(L);
+			// GC
+			lua_pushcfunction(L, close);
+			lua_setfield(L, -2, "__gc");
+
+			// Fields
+			lua_newtable(L);
+			lua_pushstring(L, "texture"); lua_setfield(L, -2, "type");
+			setfn(L, close, "close");
+
+			// Binding
+			lua_setfield(L, -2, "__index");
+
+			lua_setfield(L, LUA_REGISTRYINDEX, "__texture_mt");
+			lua_getfield(L, LUA_REGISTRYINDEX, "__texture_mt");
+		}
+		lua_setmetatable(L, -2);
+		p->text = (SDL_Texture * )lua_touserdata(L, -2);
+		SDL_QueryTexture(p->text, NULL, NULL, &p->w, &p->h);
+		lua_pushvalue(L, -3);
+		lua_setuservalue(L, -2);   // 绑定这个Rendere userdata
+
+		// stack balance
+		lua_remove(L, lua_gettop(L) - 1); // 删除lightuserdata
+		lua_remove(L, lua_gettop(L) - 1); // 删除rendere userdata
+	}
+};
+
+int LuaRectPointToRect(lua_State* L, int index, SDL_Rect& rect)
+{
+	if (lua_getfield(L, index, "type") != LUA_TSTRING)
+	{
+		lua_pop(L, 1);
+		return -1;
+	}
+
+	const char* type = lua_tostring(L, -1);
+	if (strcmp(type, "point") == 0)
+	{
+		lua_pop(L, 1);
+		lua_getfield(L, index, "x");
+		rect.x = lua_tointeger(L, -1);
+		lua_pop(L, 1);
+		lua_getfield(L, index, "y");
+		rect.y = lua_tointeger(L, -1);
+		lua_pop(L, 1);
+
+		return 1;
+	}
+	else if (strcmp(type, "rect") == 0)
+	{
+		lua_pop(L, 1);
+		lua_getfield(L, index, "x");
+		rect.x = lua_tointeger(L, -1);
+		lua_pop(L, 1);
+		lua_getfield(L, index, "y");
+		rect.y = lua_tointeger(L, -1);
+		lua_pop(L, 1);
+		lua_getfield(L, index, "w");
+		rect.w = lua_tointeger(L, -1);
+		lua_pop(L, 1);
+		lua_getfield(L, index, "h");
+		rect.h = lua_tointeger(L, -1);
+		lua_pop(L, 1);
+
+		return 0;
+	}
+	else
+	{
+		return -1;
+	}
+}
+
+struct Surface
+{
+	SDL_Surface* surf;
+
+	static int close(lua_State* L)
+	{
+		check(L, { LUA_TUSERDATA });
+		cout << "In Surface::close" << endl;
+		Surface* p = (Surface*)lua_touserdata(L, 1);
+		if (p->surf)
+		{
+			SDL_FreeSurface(p->surf);
+			p->surf = nullptr;
+		}
+		return 0;
+	}
+
+	static void create(lua_State* L) // -1, +1
+	{
+		cout << "In Surface::create" << endl;
+		Surface* p = (Surface*)lua_newuserdata(L, sizeof(Surface));
+		// Metatable
+		lua_getfield(L, LUA_REGISTRYINDEX, "__surface_mt");
+		if (lua_type(L, -1) == LUA_TNIL)
+		{
+			lua_pop(L, 1);
+			lua_newtable(L);
+			// GC
+			lua_pushcfunction(L, close);
+			lua_setfield(L, -2, "__gc");
+
+			// Fields
+			lua_newtable(L);
+			lua_pushstring(L, "surface"); lua_setfield(L, -2, "type");
+			setfn(L, close, "close");
+
+			// Binding
+			lua_setfield(L, -2, "__index");
+
+			lua_setfield(L, LUA_REGISTRYINDEX, "__surface_mt");
+			lua_getfield(L, LUA_REGISTRYINDEX, "__surface_mt");
+		}
+		lua_setmetatable(L, -2);
+		p->surf = (SDL_Surface*)lua_touserdata(L, -2);
+
+		// stack balance
+		lua_remove(L, lua_gettop(L) - 1); // 删除lightuserdata
+	}
+};
+
 struct Renderer
 {
 	SDL_Renderer* rnd;
@@ -210,6 +364,7 @@ struct Renderer
 	static int close(lua_State* L)
 	{
 		check(L, { LUA_TUSERDATA });
+		cout << "In Renderer::close" << endl;
 		Renderer* p = (Renderer*)lua_touserdata(L, 1);
 		if (p->rnd)
 		{
@@ -235,10 +390,50 @@ struct Renderer
 		return 0;
 	}
 
+	static int loadTexture(lua_State* L)
+	{
+		check(L, { LUA_TUSERDATA, LUA_TSTRING });
+		Renderer* p = (Renderer*)lua_touserdata(L, 1);
+		const char* filepath = lua_tostring(L, 2);
+		SDL_Texture* text = IMG_LoadTexture(p->rnd, filepath);
+		lua_pushvalue(L, 1);
+		lua_pushlightuserdata(L, text);
+		Texture::create(L);
+		return 1;
+	}
+
+	static int copy(lua_State* L)
+	{
+		check(L, { LUA_TUSERDATA, LUA_TUSERDATA, LUA_TTABLE, LUA_TTABLE });
+		Renderer* p = (Renderer*)lua_touserdata(L, 1);
+
+		return 0;
+	}
+
+	static int copyTo(lua_State* L)
+	{
+		check(L, { LUA_TUSERDATA, LUA_TUSERDATA, LUA_TTABLE });
+		Renderer* r = (Renderer*)lua_touserdata(L, 1);
+		Texture* t = (Texture*)lua_touserdata(L, 2);
+		SDL_Rect rect;
+		int ret = LuaRectPointToRect(L, 3, rect);
+		if (ret < 0)
+		{
+			luaL_error(L, "Bad argument #%d. Point or Rect expected, got %s", 3, lua_typename(L, lua_type(L, 3)));
+		}
+		if (ret == 1)
+		{
+			rect.w = t->w;
+			rect.h = t->h;
+		}
+		SDL_RenderCopy(r->rnd, t->text, NULL, &rect);
+		return 0;
+	}
+
 	static int create(lua_State* L)
 	{
 		check(L, { LUA_TUSERDATA });
-		cout << "In SDLWindow::Create" << endl;
+		cout << "In Renderer::create" << endl;
 		Renderer* p = (Renderer*)lua_newuserdata(L, sizeof(Renderer));
 		lua_getfield(L, LUA_REGISTRYINDEX, "__renderer_mt");
 		if (lua_type(L, -1) == LUA_TNIL)
@@ -254,7 +449,10 @@ struct Renderer
 			lua_pushstring(L, "renderer"); lua_setfield(L, -2, "type");
 			setfn(L, close, "close");
 			setfn(L, update, "update");
-			setfn(L, clear, "clear");			
+			setfn(L, clear, "clear");
+			setfn(L, loadTexture, "loadTexture");
+			setfn(L, copy, "copy");
+			setfn(L, copyTo, "copyTo");
 
 			// Set __index of metatable.
 			lua_setfield(L, -2, "__index");
@@ -263,25 +461,283 @@ struct Renderer
 			lua_getfield(L, LUA_REGISTRYINDEX, "__renderer_mt");
 		}
 		lua_setmetatable(L, -2);
-
+		// 绑定当前Renderer的对象到自身, 防止SDL_Window被提前销毁.
+		lua_pushvalue(L, 1);
+		lua_setuservalue(L, -2);
 		// Internal logic
 		p->rnd = SDL_CreateRenderer(static_cast<Window*>(lua_touserdata(L, 1))->wnd, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC | SDL_RENDERER_TARGETTEXTURE);
 		return 1;
 	}
 };
 
+int LuaColorToColor(lua_State* L, int index, SDL_Color& c)
+{
+	if (lua_getfield(L, index, "type") != LUA_TSTRING)
+	{
+		lua_pop(L, 1);
+		return -1;
+	}
+
+	const char* type = lua_tostring(L, -1);
+	if (strcmp(type, "color") == 0)
+	{
+		lua_pop(L, 1);
+		lua_getfield(L, index, "r");
+		c.r = lua_tointeger(L, -1);
+		lua_pop(L, 1);
+		lua_getfield(L, index, "g");
+		c.g = lua_tointeger(L, -1);
+		lua_pop(L, 1);
+		lua_getfield(L, index, "b");
+		c.b = lua_tointeger(L, -1);
+		lua_pop(L, 1);
+		lua_getfield(L, index, "a");
+		c.a = lua_tointeger(L, -1);
+		lua_pop(L, 1);
+
+		return 0;
+	}
+	else
+	{
+		return -1;
+	}
+}
+
+struct Font
+{
+	TTF_Font* font;
+
+	static int close(lua_State* L)
+	{
+		check(L, { LUA_TUSERDATA });
+		cout << "In Font::close" << endl;
+		Font* f = (Font*)lua_touserdata(L, 1);
+		if (f->font)
+		{
+			TTF_CloseFont(f->font);
+			f->font = nullptr;
+		}
+		return 0;
+	}
+
+	static int renderText(lua_State* L)
+	{
+		Renderer* r = nullptr;
+		Font* f = nullptr;
+		const char* text = nullptr;
+		SDL_Color c;
+		if (lua_gettop(L) >= 4)
+		{
+			check(L, { LUA_TUSERDATA, LUA_TUSERDATA, LUA_TSTRING, LUA_TTABLE });
+			f = (Font*)lua_touserdata(L, 1);
+			r = (Renderer*)lua_touserdata(L, 2);
+			text = lua_tostring(L, 3);
+			if (LuaColorToColor(L, 4, c) < 0)
+			{
+				luaL_error(L, "Bad argument #%d. Color expected, got %s", 4, lua_typename(L, lua_type(L, 4)));
+			}
+		}
+		else
+		{
+			check(L, { LUA_TUSERDATA, LUA_TSTRING, LUA_TTABLE });
+			f = (Font*)lua_touserdata(L, 1);
+			text = lua_tostring(L, 3);
+			if (LuaColorToColor(L, 4, c) < 0)
+			{
+				luaL_error(L, "Bad argument #%d. Color expected, got %s", 4, lua_typename(L, lua_type(L, 4)));
+			}
+		}
+
+		SDL_Surface* surf = TTF_RenderText_Blended(f->font, text, c);
+
+		if (r)
+		{
+			SDL_Texture* text = SDL_CreateTextureFromSurface(r->rnd, surf);
+			SDL_FreeSurface(surf);
+			lua_pushvalue(L, 2);
+			lua_pushlightuserdata(L, text);
+			Texture::create(L);
+		}
+		else
+		{
+			lua_pushlightuserdata(L, surf);
+			Surface::create(L);
+		}
+		return 1;
+	}
+
+	static int create(lua_State* L)
+	{
+		check(L, { LUA_TSTRING, LUA_TNUMBER });
+		cout << "In Font::create" << endl;
+		Font* f = (Font*)lua_newuserdata(L, sizeof(Font));
+		lua_getfield(L, LUA_REGISTRYINDEX, "__font_mt");
+		if (lua_type(L, -1) == LUA_TNIL)
+		{
+			lua_pop(L, 1);
+			lua_newtable(L);
+			// GC
+			lua_pushcfunction(L, close);
+			lua_setfield(L, -2, "__gc");
+
+			// Fields
+			lua_newtable(L);
+			lua_pushstring(L, "font"); lua_setfield(L, -2, "type");
+			setfn(L, close, "close");
+			setfn(L, renderText, "renderText");
+
+			// Set __index of metatable.
+			lua_setfield(L, -2, "__index");
+
+			lua_setfield(L, LUA_REGISTRYINDEX, "__font_mt");
+			lua_getfield(L, LUA_REGISTRYINDEX, "__font_mt");
+		}
+		lua_setmetatable(L, -2);
+		const char* filename = lua_tostring(L, 1);
+		int fontsz = lua_tointeger(L, 2);
+		f->font = TTF_OpenFont(filename, fontsz);
+
+		return 1;
+	}
+};
+
+struct Music
+{
+	Mix_Music* music;
+
+	static int close(lua_State* L)
+	{
+		check(L, { LUA_TUSERDATA });
+		cout << "In Music::close" << endl;
+
+		Music* m = (Music*)lua_touserdata(L, 1);
+		if (m->music)
+		{
+			Mix_FreeMusic(m->music);
+			m->music = nullptr;
+		}
+		return 0;
+	}
+
+	static int create(lua_State* L)
+	{
+		check(L, { LUA_TSTRING });
+		cout << "In Music::create" << endl;
+
+		Music* m = (Music*)lua_newuserdata(L, sizeof(Music));
+		lua_getfield(L, LUA_REGISTRYINDEX, "__music_mt");
+		if (lua_type(L, -1) == LUA_TNIL)
+		{
+			lua_pop(L, 1);
+			lua_newtable(L);
+			// GC
+			lua_pushcfunction(L, close);
+			lua_setfield(L, -2, "__gc");
+
+			// Fields
+			lua_newtable(L);
+			lua_pushstring(L, "music"); lua_setfield(L, -2, "type");
+			setfn(L, close, "close");
+
+			// Set __index of metatable.
+			lua_setfield(L, -2, "__index");
+
+			lua_setfield(L, LUA_REGISTRYINDEX, "__music_mt");
+			lua_getfield(L, LUA_REGISTRYINDEX, "__music_mt");
+		}
+		lua_setmetatable(L, -2);
+
+		const char* filename = lua_tostring(L, 1);
+		m->music = Mix_LoadMUS(filename);
+		cout << "Load music error: " << SDL_GetError() << endl;
+
+		return 1;
+	}
+};
+
+struct MusicPlayer
+{
+	static int close(lua_State* L)
+	{
+		check(L, { LUA_TUSERDATA });
+		cout << "In MusicPlayer::close" << endl;
+
+		return 0;
+	}
+
+	static int play(lua_State* L)
+	{
+		check(L, { LUA_TUSERDATA, LUA_TUSERDATA });
+		MusicPlayer* p = (MusicPlayer*)lua_touserdata(L, 1);
+		Music* m = (Music*)lua_touserdata(L, 2);
+		cout << "Play music ret: " << Mix_PlayMusic(m->music, 1) << " " << SDL_GetError() << endl;
+		return 0;
+	}
+
+	static int create(lua_State* L)
+	{
+		cout << "In MusicPlayer::create" << endl;
+
+		MusicPlayer* m = (MusicPlayer*)lua_newuserdata(L, sizeof(MusicPlayer));
+		lua_getfield(L, LUA_REGISTRYINDEX, "__musicplayer_mt");
+		if (lua_type(L, -1) == LUA_TNIL)
+		{
+			lua_pop(L, 1);
+			lua_newtable(L);
+			// GC
+			lua_pushcfunction(L, close);
+			lua_setfield(L, -2, "__gc");
+
+			// Fields
+			lua_newtable(L);
+			lua_pushstring(L, "musicplayer"); lua_setfield(L, -2, "type");
+			setfn(L, close, "close");
+			setfn(L, play, "play");
+
+			// Set __index of metatable.
+			lua_setfield(L, -2, "__index");
+
+			lua_setfield(L, LUA_REGISTRYINDEX, "__musicplayer_mt");
+			lua_getfield(L, LUA_REGISTRYINDEX, "__musicplayer_mt");
+		}
+		lua_setmetatable(L, -2);
+
+		return 1;
+	}
+};
+
 #define reg_in_lua(L, cfunc, name) lua_pushcfunction(L, cfunc); lua_setglobal(L, name)
 
+void check_init(lua_State* L, const char* name, int ret, int expected = 0)
+{
+	if (ret != expected)
+	{
+		luaL_error(L, "Failed to initialize %s. ret: %d. expected: %d. SDLError: %s", name, ret, expected, SDL_GetError());
+	}
+}
+
 int InitEngine(lua_State* L)
 {
-	SDL_Init(SDL_INIT_EVERYTHING);
-	IMG_Init(IMG_INIT_JPG | IMG_INIT_PNG);
-	TTF_Init();
-	Mix_Init(MIX_INIT_MP3);
+	int ret;
+	ret = SDL_Init(SDL_INIT_EVERYTHING);
+	check_init(L, "SDL", ret);
+	ret = IMG_Init(IMG_INIT_JPG | IMG_INIT_PNG);
+	check_init(L, "IMG", ret, IMG_INIT_JPG | IMG_INIT_PNG);
+	ret = TTF_Init();
+	check_init(L, "TTF", ret);
+	ret = Mix_Init(MIX_INIT_MP3 | MIX_INIT_MOD | MIX_INIT_OGG );
+	check_init(L, "MIX", ret, MIX_INIT_MP3 | MIX_INIT_MOD | MIX_INIT_OGG);
+
+	ret = Mix_OpenAudio(44100, MIX_DEFAULT_FORMAT, 2, 512);
+	check_init(L, "AUDIO", ret);
+	Mix_AllocateChannels(16);
 
 	lua_newtable(L);
 	reg_in_lua(L, Window::create, "Window");
 	reg_in_lua(L, Renderer::create, "Renderer");
+	reg_in_lua(L, Font::create, "Font");
+	reg_in_lua(L, Music::create, "Music");
+	reg_in_lua(L, MusicPlayer::create, "MusicPlayer");
 
 	return 0;
 }